NASA's delay turns shuttle liftoff into letdown

Safety glitch postpones mission until at least Monday

CAPE CANAVERAL, Fla. - The fuel tanks were filled. The astronauts were on their way to the craft.

The crowds lining the roadsides were ready for the thunder of the rockets, and the wounded congresswoman was ready for a personal triumph.

Then, in a moment, reality put the most-watched space-shuttle mission in years on hold.

Detecting an electrical failure, NASA announced a scrub of the launch of the space shuttle Endeavour less than four hours before liftoff Friday morning, saying the mission would be delayed at least three days.

The shuttle had been set to lift off at 12:47 p.m. Arizona time, with astronaut Mark Kelly in the commander's seat and his wife, Rep. Gabrielle Giffords, watching nearby.

Giffords has been in intensive rehabilitation at a Houston hospital after suffering a gunshot wound to the head, and her staff said her first trip away had long been a goal.

Instead, the flight crew was pulled back, and Giffords and hundreds of thousands of other people amassed on Florida's Space Coast were forced to wait a little longer.

Despite the setback, the event took on historic proportions, with more spectators and media coverage than any launch in recent years, and a rare presidential visit.

Delays are common in shuttle launches, where a small technical glitch or weather problem can become catastrophic once the craft is traveling thousands of miles per hour.

"I would rather be on the ground wishing I was flying than be in the air wishing I was on the ground," said Mike Leinbach, NASA's shuttle-launch director, in a post-scrub news briefing.

The problem, according to NASA, was in an auxiliary power unit that helps guide the main engines in flight and during re-entry. Heaters that prevent lines from freezing during the extreme cold of orbit had failed.

NASA said it tried repeatedly to get the heaters up and running again but could not. Another attempt at a launch could come Monday.

Just after the delay was announced, Giffords' staff, which for months has released optimistic messages about her progress toward attending the launch, sent out a tweet: "Bummed about the scrub!! But important to make sure everything on shuttle is working properly."

Road to recovery, flight

Friday's launch was set to conclude a chapter of history that mixed politics, love and spaceflight.

The Endeavour mission was thrust into the national spotlight after a mass shooting outside Tucson on Jan. 8.

Six people were killed at a civic event put on by Giffords' office. Among the survivors, Giffords was the most critically wounded, taking a bullet through one half of her brain.

Kelly, in training in Houston, rushed to her side.

Since their wedding in 2007, the couple had pursued their high-powered careers in Washington and Houston while also spending time together in Tucson.

Over the following days, his public briefings on her recovery at Tucson's University Medical Center led to public speculation over whether he would return to the space mission.

Obama, too, became a part of the story, attending a Tucson memorial service for the victims.

There, he made the first public announcement that Giffords had opened her eyes.

Some stories, for reasons that cannot be quantified, become important to people. Across the country, Giffords' recovery became one of those stories.

Giffords was transferred to a rehabilitation hospital in Houston, and Kelly returned to his training.

The plan was clear: Kelly would fly, and if Giffords was ready to travel, she would be in Florida to see him off.

Nearly four months later, news helicopters captured Giffords' first public steps as she climbed aboard a NASA jet for the trip.

Giffords, still secluded during her rehabilitation, was to view the launch from a spot that had not been publicly disclosed.

One likely location was the roof of the Launch Control Center, where crew families watch shuttle launches. That area underwent modifications this week.

On Wednesday and Thursday, a white tarp was wrapped around the fencing on top of the roof. This would have blocked views from the ground.

A black tarp was wrapped around the external staircase that people use to access the top of the building.

The modifications may have been made for presidential security or for Giffords' privacy.

Shortly after the launch was canceled, the president arrived. He greeted Kelly in a corridor before a private meeting with Giffords.

"I bet you were hoping to see a rocket launch today," Kelly said.

Obama said, "We were hoping to see you."

Second-to-last launch

The shuttle drew throngs of spectators to Florida.

Because the Endeavour's launch will be the second to last of the shuttle program, many flocked to the region to see a liftoff while they still had the chance.

Some estimates pegged the number at 750,000.

Some were there because of a personal connection to Giffords.

Shortly after the launch, her office released a photo of Giffords aide Ron Barber talking to NASA Administrator Charles Bolden.

Barber, Giffords' district director, was wounded in the face and the leg during the shooting.

Ross Zimmerman also was in Florida for the launch. He is the father of Gabe Zimmerman, a community-outreach staffer who worked for Giffords in Tucson. Gabe died in the shooting.

Ross said he was disappointed by the scrubbing of the launch Friday. But that was not the real reason he came.

"I came here to spend time with the people from the office, the people who knew Gabe, and we have done a lot of that," Ross said. "It has been very nice."

Scientific meaning

The Endeavour's launch had meaning far beyond Giffords' recovery.

For science, the shuttle carries a spectrometer that will analyze space particles once aboard the International Space Station.

The device is built to detect dark matter, mysterious particles believed to have been created in the big bang.

The measurements may give scientists new clues about the origins of the universe.

For NASA, the launch represented the door closing on a program that has defined the agency for 30 years. Only one more shuttle flight is planned before the agency moves to longer-range projects.

Throughout Friday morning, questions arose about whether the launch would happen.

The questions were about whether clouds at the space center would clear and whether wind gusts would settle enough to allow for a safe takeoff.

But less than four hours before the scheduled liftoff time, with the sun breaking through, the Endeavour was fueled and ready to go and Kelly and the five other astronauts were heading toward the launch site.

In the Launch Control Center, the traditional buffet of beans and cornbread - enjoyed only after a successful launch - was being prepared.

The silver van carrying the astronauts suddenly made a U-turn, heading back toward crew quarters.

"We'll fly no orbiter before its time," Leinbach, the launch director, said later. "And today, she just wasn't ready to go."

President Barack Obama and first lady Michelle Obama meet with astronaut Mark Kelly, Gabrielle Giffords' husband and commander of the space shuttle Endeavour, on Friday after the shuttle's launch was delayed.